| 摘要 |
The invention concerns a method of compensating the temperature in pressure sensors of the kind wherein a pressure is sensed by means of a diaphragm connected in an electric bridge circuit. The latter comprises four resistances (2, 3, 4, 5) connected in series in a quadrilateral bridge (l), a so called Wheatstone bridge. These resistances change their values in response to such alterations in the diaphragm configuration as are caused by changes in the detected pressure. In two diagonally opposite points (8, 9) the bridge is supplied with a constant current (ik). First measurement points of offset output signals emanating from the bridge (l) in the pressure sensor at a number of temperature levels are plotted in a first graph indicating the voltage as a function of the resulting resistance (RB) of the bridge (l), whereupon adjacent measurement points are interconnected by straight lines and calculation is effected through interpolation between the measurement points. The sensitivity of the pressure sensor such as voltage/pressure unit, is determined in a corresponding manner at different temperature levels by plotting second measurement points in a second graph indicating the sensitivity as a function of the resulting resistance (RB). In a similar way the last mentioned measurement points are interconnected by means of straight lines and calculation is effected through interpolation between the measurement points. The resulting curves are processed in a computer, whereupon a signal from the pressure reading provides a directly temperature-compensated pressure value which may be read from a third graph indicative of an output signal that is proportional to the prevailing pressure. |
